I'm not that familiar with Landeskronen, however a quick google brings up a good selection for comparison.
Stylistically your vase looks more central European to my eye. For example, if you compare some Josef Hoffmann panel cut glass vases stylistically they look much closer to your piece than Venetian glass. (not saying your piece is a Hoffman design, however the style is comparable)
The age of your vase is tricky, the enamelling looks to be in very good condition, also there is not a tremendous amount of base wear from what I can see. I presume the top rim of your vase is cut..?
Sure there is such a thing as Venetian cut glass in as much as its just another cold working process, there's lots of Murano facet cut glass and battuto glass for example, however, the style is quite different to your vase.